1. Field of the Invention
This invention relates to a nozzle for accelerating the rate of flow of compressed air to supersonic speed.
2. Description of the Prior Art
Tools for delivering a high speed flow of air for cleaning and excavating are known.
For example, a tool known as the Supersonic Air Knife is available from Briggs Technology Inc. for use in manual excavation tasks such as exposing gas mains by breaking apart and pushing out soil.
U.S. Pat. No. 4,360,949 to Wilson shows a pneumatic cleaning device which uses air under pressure and Bonnevalle U.S. Pat. No. 3,511,326 shows a device for injecting a mixture of air and water under pressure for restoring clogged wells.
A converging-diverging venturi nozzle using high-pressure water is shown in U.S. Pat. No. 3,620,457 to Pearson and a nozzle for discharging drilling fluid in a drill bit is shown in Sorenson U.S. Pat. No. 4,603,750.
However, no prior art compressed air nozzle has been totally satisfactory for manual excavation to uncover buried pipes, electrical cables and the like. The present invention relates to a compressed air nozzle which is useful in such excavating tasks.